1. Field of the Invention
The present invention relates to a piston-stroke adjusting mechanism of a hydraulic tool and, more particularly, to a piston-stroke adjusting mechanism thereof which is constructed such that an adjust pin for adjusting the stroke is mounted in a piston in a cylinder.
2. Description of the Prior Art
Conventionally, this type of hydraulic tool includes one which is shown in FIG.4. Specifically, a hydraulic tool 43 has a body 44, at the right side of which there is provided an oil tank 45, and at a substantially central portion of which there are provided a ram cylinder 46 and ram 47 for supplying a working fluid. At a forward portion of the body 44 there is provided a cylinder section 49 containing a piston 48. A stationary head 50 is mounted on a forward end of the tool in such a manner that it is secured to the body 44 integrally.
A grip/handle 51 which is in the form of a hollow cylinder is mounted on the body 44, within which the above-mentioned oil tank 45 is received.
The ram 47 is swingably mounted with a pressurizing handle 52. When the pressurizing handle 52 is swung several times, the oil in the oil tank 45 is allowed to pass through check valves 53 and 54 and thus is supplied to a bottom section of the piston 48 in the cylinder 49. The piston 48 is thereby raised against the biasing force of a spring 55.
As a result, a male die (movable head) 56 fixed on a head section of the piston 48 is caused to slide jointly with the piston 48 toward a female die 57 provided on the stationary head 50, thus permitting the tool to conduct a terminal handling or processing operation.
However, when conducting the terminal processing operation for, for example, electric wires by using the above-mentioned conventional hydraulic tool, it is necessary to replace the head by another head suitable for the diameter of the electric wire to be processed where this diameter has been changed into a smaller one in particular. Since the conventional tool has a fixed stroke of piston, a useless stroke is produced by the time when the male die (movable head) made to move jointly with the piston abuts on the small-diameter wire and grips the same. This means that the pressurizing handle (ram) must unnecessarily be swung by the extent corresponding to said useless stroke. This means that a larger amount of labor than required must be spent, failing to enhance the working efficiency.